Temperature dependence of mobility and carrier density in InN films.

We investigate the temperature dependence of Hall mobility μ and carrier density N_e for thin InN films grown by molecular-beam epitaxy and plasma source molecular-beam epitaxy over three orders-of-magnitude difference in their carrier density: for the low-density film N_e=5.8×10¹⁷/cm³ and for the high-density film N_e=3.2×10²⁰/cm³. In both the films, for temperature up to 300 K, a large temperature-independent concentration of carriers is observed. For higher temperatures, however, carrier density increases with temperature. The characteristic behavior of the mobility for the low-density film is different from that of the high-density film, particularly for temperatures less than 300 K. The low-density film shows a peak behavior in the mobility around 250 K in contrast to the temperature-independent mobility observed for the high-density film for T<300 K. We investigate theoretically the concentrations of donor, acceptor, and threading dislocations for both the films and also discussed various electron-scattering mechanisms which contribute to the mobility in these films. [ABSTRACT FROM AUTHOR]